SALT LAKE CITY — The Salt Lake County District Attorney's Office has concluded that a Cottonwood Heights police officer was justified in shooting a teenage suspect following a car chase through Salt Lake County around 3 a.m. on September 3.

District Attorney Sim Gill said the 17-year-old suspect, identified only as 'A.J.' took off from a traffic stop in the Union Park area of Cottonwood Heights and led police on a chase that exceeded speeds of 100 mph. The suspect exited I-15 at 1300 S and drove up an embankment at the I-15 overpass.

Cottonwood Heights Police Sergeant Chris McHugh then followed the suspect in his patrol vehicle as the suspect walked away, and he said he saw the teen reach into a backpack.

"McHugh sees him open the backpack and take something out. In the process of taking that out, that's when he drops the box of bullets," Gill explained. "He also sees him take and put something down his pants."

A photo Gill showed at the Wednesday press conference showed a box of .22 calibur bullets sitting on the ground near a backpack. He said Sergeant McHugh feared those actions could mean A.J. had a gun in his pants.

But, Gill said A.J. began complying with police commands, leading to de-escalation.

"At the point he actually holsters his gun," Gill said, of Sgt. McHugh.

McHugh put his gun away, but kept his taser out. However Gill said McHugh noticed A.J. was wearing a thick leather coat, and realized the taser might not be effective.

Gill played a piece of audio from the investigative interview with Sgt. McHugh, where he explains what happened next as he approached A.J. to take him into custody.

"He starts to roll over on me," Sgt. McHugh said in the interview. "Once he rolls over, his hand immediately goes down his pants."

Sgt. McHugh explained it was similar to what he saw when the suspect was first walking away from police.

"His elbow starts to come up. At that point I start moving off line, trying to create some distance, giving him commands, `Stop, stop stop, stop!` He doesn't stop. I fire a round," Sgt. McHugh recounted.

At the press conference, Gill replayed body camera footage showing the moments Sgt. McHugh puts his gun away in the holster, then where the suspect appears to shift his body and put his hand into his pants.

The single shot hit the teen, who was then taken to Intermountain Medical Center in stable condition.

Gill said medical personnel at the hospital found a fully loaded .22-caliber revolver hidden in the suspect's underwear.

"He believed that the deadly force was necessary to prevent death or serious bodily injury," Gill said.